(a) Field of the Invention
The present invention relates to a method for implementing spatial division multiple access in a system including a base station, a wireless repeater, and a terminal for mobile communication. In detail, the present invention relates to a signal processing method and a signal transmitting method of a base station that can provide spatial division multiple access in the system.
(b) Description of the Related Art
Among wireless transmission technologies, many technologies of increasing sector throughput using multiple antennas have been researched. Spatial division multiple access (SDMA) means a method that allows one base station to allocate the same resource to several terminals, and transmits and receives one or more data streams. At this time, in order to obtain an effect of increasing the sector throughput using the SDMA, a plurality of data streams should be simultaneously transmitted as maximally as possible, which can be achieved only when a received signal to noise ratio (SNR) of a plurality of terminals participating in multiple transmission is high. However, spatial multiplexing can be achieved only in an area near a base station having a high received signal to noise ratio of the terminals and is difficult to apply to terminals far away from the base station. In other words, there is a problem in that the spatial multiplexing can be applied only to some areas within cells.
A repeater mainly is used to remove shadow areas within the cells, or can be used to expand coverage. That is, when the repeater is installed in shadow areas, since the signal to noise ratio is increased, the shadow areas are removed, and when the repeater is installed in areas out of a cell radius of the base station, the coverage is expanded.
As the wireless repeater, a radio frequency (RF) repeater, which receives, amplifies, and repeats carriers transmitted from the base station into the cell as it is, has been mainly used. However, since the existing RF repeater does not perform signal processing for the repeater in the base station, there is a problem in that it is not used to increase the sector throughput.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.